Story highlights

Washington (CNN)Republican Rep. Scott Rigell is voting for Libertarian Gary Johnson for president over his party's nominee, Donald Trump.

Rigell, who has announced he will not run for re-election this year in his Virginia district, is the second Republican member of Congress to announce that he'll vote for someone other than Trump. Retiring New York Rep. Richard Hanna wrote in an op-ed for Syracuse.com this week that he'll instead back Democratic nominee Hillary Clinton.

Rigell's announcement came in an interview with The New York Times published on Saturday, and Kaylin Minton, a spokeswoman for Rigell, confirmed the report's accuracy to CNN.

JUST WATCHED

GOP Congressman: I won't vote for Trump in November

MUST WATCH

GOP Congressman: I won't vote for Trump in November02:53

Hanna and Rigell's defections come as other notable Republicans have said they will either not vote for Trump or will back other candidates. Earlier this week, longtime Chris Christie aide Maria Comella told CNN's Jamie Gangel she plans to vote for Clinton, and Sally Bradshaw, Jeb Bush's top adviser, told Gangel she's leaving the Republican Party over Trump and will vote for Clinton in Florida if the race there is close.

Amid Republican infighting over its anti-establishment nominee, the Clinton and Johnson campaigns have sought to grow their bases of support. For example, Whitman said she backed Clinton following a direct phone call from the former secretary of state.

Johnson said his campaign has reached out to Republican 2012 nominee Mitt Romney, who has pointedly refused to back Trump and said he's considering voting Libertarian.

A spokeswoman for Rep. Mike Coffman, a Republican who hails from a competitive district in Colorado and recently put up a web video saying he "doesn't care" for Trump, said the congressman had spoken with Libertarian vice presidential nominee William Weld. Coffman has yet to declare his support for any candidate.